Various air scrubbing devices exist today and are on the market. In general, those which utilize water of some form to remove the contaminant from the air admix the air and water through turbulent procedures. They do not utilize the advantages of a slow-moving circular air stream giving the time and lesser velocity needed for the water to impinge upon the contaminants and adhere to them, coupled with a continuing annular compression factor, to force additional particles together.
Prior art devices include cleaners with circular air flow such as those shown in Seymour U.S. Pat. No. 1,130,849, Fisher U.S. Pat. No. 2,354,674, Johnstone U.S. Pat. No. 2,604,185, Gordon U.S. Pat. No. 2,807,450, and Jepsen U.S. Pat. No. 3,488,927. Annular cleaners with vanes to create the circular motion include Smith U.S. Pat No. 2,728,409 and Pearl U.S. Pat. No. 3,348,830. Scrubbers with reversing air flow include Fisher U.S. Pat. No. 2,259,032, Smith U.S. Pat. No. 2,728,409 and Gordon U.S. Pat. No. 2,807,450. Various water washing techniques are shown in many of the above patents, McIlvaine U.S. Pat. No. 3,077,714 and Wisting U.S. Pat. No. 3,336,733.